It seems like everyone is talking about — or taking — GLP-1 medications like Ozempic, Wegovy, Saxenda and Mounjaro. These drugs have changed the conversation about weight loss, and for good reason: they work, and they have helped millions of people. So patients now ask me a very fair question: with medications this effective, does anyone still need bariatric surgery?
The answer, backed by a growing body of research, is yes — and for certain patients, surgery remains not just an option, but the most effective and most durable treatment available.
What the GLP-1 era has taught us
GLP-1 medications typically produce 15–20% total body weight loss in clinical trials. But two hard truths have emerged as these drugs have moved from trials into the real world.
First, most people stop taking them. Studies show roughly half of patients discontinue GLP-1 therapy within the first year — because of cost, supply issues, or side effects such as nausea and gastrointestinal intolerance.
Second, the weight comes back when they stop. In the STEP-10 trial, patients regained over 40% of their lost weight within 28 weeks of stopping semaglutide. In SURMOUNT-4, patients regained more than half of their weight loss within a year of stopping tirzepatide. These medications manage obesity the way insulin manages diabetes — only for as long as you keep taking them, quite possibly for life.
How surgery compares
Modern bariatric surgery — most commonly the sleeve gastrectomy or gastric bypass, performed through small keyhole incisions — changes the body's underlying metabolism and hormonal signalling, not just appetite from week to week.
| Factor | GLP-1 Medications | Bariatric Surgery |
|---|---|---|
| Typical weight loss | 15–20% of total body weight | 25–35% of total body weight |
| Durability | Weight returns after stopping; fewer than half maintain ≥10% loss | 96% of patients maintain ≥10% loss in head-to-head data |
| Type 2 diabetes | Improves control while on treatment | Remission in the majority — many come off insulin entirely |
| Duration of treatment | Weekly injections, likely lifelong | One operation, lifelong effect |
| Long-term cost | Ongoing monthly expense, often for years | One-time cost |
A large real-world analysis published in 2025 found that surgical patients lost roughly five times more weight at two years than patients on GLP-1 therapy. And at accredited centres, the safety profile of keyhole bariatric surgery is comparable to gallbladder surgery, with complication rates of around 3% and mortality of roughly 0.1%.
Durability Is Surgery's Great Advantage
The single most important lesson of the GLP-1 era is this: obesity is a chronic disease, and any treatment that stops working when you stop taking it is, by definition, a temporary treatment.
Surgery permanently changes gut hormone signalling — including the same GLP-1 pathway these drugs mimic. That is why surgical weight loss endures, and why type 2 diabetes goes into remission after surgery at rates no medication has matched.
Who should seriously consider surgery?
Using Asian BMI criteria — which apply to most Malaysians — you are a candidate for bariatric surgery if you have:
- A BMI of 37.5 or above, regardless of other medical conditions
- A BMI of 32.5 or above with an obesity-related condition such as type 2 diabetes, hypertension, sleep apnoea, or fatty liver disease
Within those criteria, surgery deserves especially serious consideration if any of the following sound familiar:
Your GLP-1 Journey Has Stalled
- You've plateaued before reaching a healthy weight
- The weight returned when you stopped the injections
- Side effects made the medication hard to tolerate
- The monthly cost is not sustainable for the long term
Your Health Is on the Line
- You have type 2 diabetes — no treatment matches surgery for durable remission
- You have sleep apnoea, joint disease, or fatty liver
- You're planning pregnancy or another operation where weight matters
- You want a definitive solution, not an open-ended prescription
It's not either/or
GLP-1s and surgery are not competitors — they are tools. Many patients use medication before surgery to reduce operative risk, or after surgery to fine-tune their long-term result. The right plan is individual, and it starts with an honest evaluation of your health, your goals, and your treatment history.
Despite decades of proven results, only a small fraction of eligible patients ever undergo bariatric surgery. If you meet the criteria above — especially if you have already given a GLP-1 a fair try — you owe it to yourself to at least have the conversation.
My honest advice: if you are on a GLP-1 and it is working well for you, that is genuinely good news — keep going with your doctor's guidance. But if you have stalled, regained, or cannot see yourself injecting forever, don't treat surgery as a last resort. For the right patient, it is the most effective treatment we have — and delaying it only means more years living with the complications of obesity.
Dr Cha Kar Huei
Consultant General Surgeon (Gastrointestinal, Bariatric & Robotic Surgery), Hospital Picaso